The Descent
A year after a tragic accident, a group of female weekend adventurers gather in the remote Appalachians to reconnect through a seemingly casual spelunking expedition. Soon after entering the cavern however, their return route collapses and the women find themselves in a claustrophobic challenge to find another way out of the subterranean chambers. Complicating things to the Nth degree is the realization that they are not alone in the dark. It takes 20 minutes for the characters to even arrive at the mouth of the cave and begin their descent. But once the meandering passes, the final act of the film provides easily some of the most unsettling set pieces in modern horror coupled by a handful of well-earned jolts, delivering with 40 minutes of straight-out, balls-to-the-wall (so to speak) grueling horror.